Integrated circuit package separators

ABSTRACT

A base having a plurality of pins extending upwardly therefrom is provided. A support is provided over the base. The support has an upper surface and a plurality of holes extending therethrough. The pins extend through the holes and upwardly beyond the upper surface of the support. An actuator is provided beneath the support. A board having a plurality of integrated circuits bonded thereto is provided. The integrated circuits form a repeating pattern of integrated circuit packages across the board, and the board has a plurality of holes extending through it. The board is placed over the support upper surface with the pins extending into the holes in the board. While the board is over the support upper surface, it is cut to separate the integrated circuit packages from one another.

RELATED PATENT DATA

This patent resulted from a divisional application of U.S. patentapplication Ser. No. 09/533,058, filed Mar. 22, 2000, and titled“Integrated Circuit Package Separators”, which is a divisionalapplication of U.S. patent application Ser. No. 09/176,479, which wasfiled on Oct. 20, 1998 now U.S. Pat. No. 6,277,671.

TECHNICAL FIELD

The invention pertains to methods of forming integrated circuitpackages, as well as to devices for separating integrated circuitpackages.

BACKGROUND OF THE INVENTION

Circuit constructions having integrated circuit (IC) chips bonded tocircuit boards (such as SIMMs and DIMMs) can be fabricated by joining ICchips on a single large circuit board comprising a plurality of theconstructions. The circuit board can be subsequently cut to separatediscrete constructions from one another. The discrete constructions arereferred to herein as integrated circuit packages. The smaller theindividual circuit packages, the more likely it is for industryprocessing to utilize the above-described method of forming the packageson a single large board and subsequently cutting individual packagesfrom the board.

An exemplary prior art process of separating integrated circuit packagesis described with reference to FIG. 1. FIG. 1 illustrates a boardassembly 10 having a plurality of IC chips 12 (only some of which arelabeled) bonded thereto. Chips 12 are aligned into individual IC packageconfigurations 14 (only some of which are labeled) to form a repeatingpattern of integrated circuit packages 14 across the board assembly 10.Dashed lines 16 are shown to illustrate the boundaries betweenindividual IC packages 14. In the shown exemplary embodiment, assembly10 comprises three separate circuit boards 11, 13 and 15. The number andsize of individual circuit boards can vary depending on the number andsize of IC packages that are ultimately to be formed.

Each of boards 11, 13 and 15 comprises a pair of lateral waste sections21, 23 and 25, respectively. The lateral waste sections 21, 23 and 25are separated from the remainder of boards 11, 13 and 15, respectively,by imaginary dashed lines 20, 22 and 24. In further processing, theindividual IC packages 14 are separated from one another by cuttingthrough boards 11, 13 and 15 along the regions illustrated by dashedlines 16. During the cutting to separate IC packages 14 from oneanother, boards 11, 13 and 15 are also cut along regions illustrated bydashed lines 20, 22 and 24 to remove waste portions 21, 23 and 25 fromthe lateral sides of the boards, and accordingly from lateral edges ofthe ultimately formed IC packages.

Orifices 19 (only some of which are labeled) are provided throughoutcircuit boards 11, 13 and 15. Specifically, pairs of orifices 19 areprovided in each IC package 14, and at least two orifices 19 areprovided in each of waste portions 21, 23 and 25.

FIG. 1 further illustrates an IC package separator 40 comprising acutting mechanism 42 (shown schematically as a cutting wheel, althoughother cutting mechanisms, such as, for example, router bits or linearblades, are known to persons of ordinary skill in the art), a retainingtable 44, and a control mechanism 45 configured to control orientationof cutting wheel 42 relative to table 44. Retaining table 44 cancomprise, for example, an x-y table (i.e., a table horizontallyadjustable S in x and y directions; an “X”, “Y” and “Z” axis system isillustrate in a lower corner of FIG. 1). Control mechanism 45 cancontrol the x and y orientation of table 44 and the z (i.e., vertical)orientation of cutting mechanism 42 to precisely cut a board retained ontable 44. Table 44, cutting mechanism 42, and control mechanism 45 canbe comprised by commercially available cutting systems, such as, forexample, Advanced Technology Incorporated's CM101 single spindle router(or, more generally, a circuit board depanelization router).

FIG. 1 also illustrates that table 44 comprises an upper platform 46. Asubplate 48 is provided over platform 46, and a stripper plate 50 isprovided over subplate 48. Subplate 48 comprises a plurality of upwardlyextending pins 60 (only some of which are labeled), and stripper plate50 comprises a number of orifices 62 configured to slide over pins 60.Subplate 48 is retained on table 44 by downwardly extending pins (notshown) which are aligned with and precisely received within orifices(not shown) extending within platform 46 of table 44.

Orifices 19 of boards 11, 13 and 15 align with pins 60. In operation,boards 11, 13 and 15 are slid over pins 60 until the pins protrudethrough orifices 19. Typically, orifices 19 are only about 0.003 incheswider than pins 60 to insure tight alignment of boards 11, 13 and 15with subplate 48. After boards 11, 13 and 15 are retained on table 44 bypins 60, cutting mechanism 42 is utilized to cut along the regionsillustrated by dashed lines 16, 20, 22 and 24. Such cutting separatesdiscrete integrated circuit packages 14 from one another, as well asfrom waste regions 21, 23 and 25. The separated circuit packages areretained on table 44 by pins 60 extending through the packages.Specifically, each of individual packages 14 comprises a pair oforifices 19 and is thereby retained on table 44 by a pair of pins 60.

After the IC packages are separated from one another, stripper plate 50is manually lifted off of subplate 42 to lift the IC packages 14 frompins 60. Once stripper plate 50 is lifted off from pins 60, theindividual IC packages can be separated from stripper plate 50. Anexemplary method of removing the IC packages from stripper plate 50 isto tilt plate 50 and allow the packages to slide off plate 50. After thepackages 14 are removed, plate 50 can be returned to over 48 and usedagain for separating IC packages.

Difficulties can occur in utilizing the assembly of FIG. 1 forseparating IC packages. For instance, separated IC packages can bebroken as stripper plate 50 is lifted from subplate 48. It would bedesirable to reduce or eliminate such problems.

SUMMARY OF THE INVENTION

In one aspect, the invention encompasses a method of forming integratedcircuit packages. A base having a plurality of pins extending upwardlytherefrom is provided. A support is provided over the base. The supporthas an upper surface and a plurality of holes extending therethrough.The pins extend through the holes and upwardly beyond the upper surfaceof the support. An actuator is provided beneath the support. A boardhaving a plurality of integrated circuits bonded thereto is provided.The integrated circuits form a repeating pattern of integrated circuitpackages across the board, and the board has a plurality of holesextending through it. The board is placed over the support upper surfacewith the pins extending into the holes in the board. While the board isover the support upper surface, it is cut to separate the integratedcircuit packages from one another. After the cutting, the support isvertically displaced by the actuator to lift the support off the pins.

In another aspect, the invention encompasses an integrated circuitpackage separator for separating integrated circuit packages from aboard. The board comprises a plurality of integrated circuits bondedthereto, and has a plurality of holes extending within it. The separatorincludes a base having a plurality of pins extending upwardly therefromand a support over the base. The support has an upper surface, aplurality of holes extending therethrough, and a pair of opposing ends.The pins extend through the holes in the support and upwardly beyond theupper surface of the support. The support and pins are configured suchthat the pins extend into the holes in the board when the board isplaced over the support upper planar surface. The separator furtherincludes a pair of actuators beneath the support and configured tovertically displace the support and lift the support off the pins.Additionally, the separator includes a cutting mechanism configured tocut the board while the board is over the support upper planar surfaceand thereby separate the integrated circuit packages from one another.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention are described below withreference to the following accompanying drawings.

FIG. 1 is a diagrammatic, perspective, exploded view of a prior art ICpackage separator and circuit board assembly.

FIG. 2 is a diagrammatic top view of an IC package separator of thepresent invention.

FIG. 3 is a diagrammatic, perspective, exploded view of an IC packageseparator of the present invention with a stripper plate of the presentinvention and a circuit board.

FIG. 4 is a view of the FIG. 3 assembly with the circuit board retainedon the IC separator.

FIG. 5 is a view of the FIG. 4 assembly after the retained circuit boardis cut to separate individual IC packages from one another.

FIG. 6 is a view of the FIG. 5 assembly after a stripper plate is liftedto release separated IC packages from retaining pins.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

This disclosure of the invention is submitted in furtherance of theconstitutional purposes of the U.S. Patent Laws “to promote the progressof science and useful arts” (Article 1, Section 8).

An IC package separator of the present invention and a method ofoperation of such separator are described below with reference to FIGS.2-6. In referring to FIGS. 2-6, similar numbering to that utilized abovein describing prior art FIG. 1 will be used, with differences indicatedby the suffix “a” or by different numerals.

Referring to FIG. 2, a separator 100 of the present invention is shownin top view. Separator 100 comprises a table 44 a and a subplate 48 aprovided over table 44 a. Table 44 a can comprise, for example, an x-ytable similar to the table 44 described above with reference to FIG. 1.Subplate 48 a, like the above-described substrate 48 of FIG. 1, can bejoined to table 44 a through a plurality of downwardly extending pins(not shown), and comprises a plurality of upwardly extending pins 60(only some of which are labeled) configured to retain a circuit boardassembly (not shown).

Subplate 48 a differs from subplate 48 of FIG. 1 in that subplate 48 acomprises notches 102 at its ends. Notches 102 are provided to allowroom for a pair of forcer plates 104 and 106 to move vertically (in andout of the page of FIG. 2) relative to table 48 a. Forcer plates 104 and106 comprise upwardly extending pins 108 and 110, respectively. Baseplate 48 a comprises an upper planar surface 115, and forcer plates 104and 106 comprise upper planar surfaces 117 and 119, respectively. Upperplanar surfaces 115, 117 and 119 ultimately support a circuit boardassembly (not shown in FIG. 2). Planar surfaces 115, 117 and 119 arepreferably substantially coplanar with one another to avoid distorting(e.g., bending) a supported circuit board assembly.

Forcer plates 104 and 106 are connected to actuators 112 and 114,respectively, configured to vertically displace forcer plates 104 and106. In the exemplary shown embodiment, forcer plates 104 and 106 areconnected to the actuators with screws 116. It is to be understood,however, that other mechanisms could be utilized for joining forcerplates 104 and 106 to actuators 112 and 114, including, for example,welding.

Actuators 112 and 114 are pneumatic (preferably air-powered) andconnected to a gas source 120. An advantage of utilizing air poweredactuators is that most wafer fabrication plants have a source of cleandry air available. Accordingly, it is relatively convenient to coupleair powered actuators 112 and 114 into existing fabrication plants bysimply connecting them to existing air lines. However, it is to beunderstood that the actuators can be powered by other sources besidesair, including, for example, other fluids, such as liquids, as well asnon-pneumatic and non-hydraulic sources, such as, for example,electricity.

Separator apparatus 100 comprises a cutting assembly (not shown in FIG.2) and a controller (not shown in FIG. 2), analogous to the cuttingassembly 42 and controller 45 of FIG. 1.

Referring to FIG. 3, IC circuit package separator 100 is shown inexploded view with a circuit board assembly 10 identical to the assemblydescribed above with reference to FIG. 1.

A stripper plate 50 a is provided between subplate 48 a and circuitboard assembly 10. Stripper plate 50 a is similar to the stripper plate50 of FIG. 1 in that plate 50 a comprises a plurality of orifices 62configured for receipt of pins 60. However, stripper plate 50 a differsfrom plate 50 of FIG. 1 in that plate 50 a also comprises orifices 122configured for receipt of upwardly extending pins 108 and 110 of forcerplates 104 and 106. Pins 108 and 110 are preferably tapered pins, suchas can be obtained from McMaster-Carr. Exemplary pins have a dimensionof 0.248 inches at base, 0.2324 inches at top, and a length of 0.75inches. The taper of the pins can assist in aligning support 50 a overthe pins during placement of support 50 a onto base 48 a.

Stripper plate 50 a further differs from plate 50 of FIG. 1 in thatplate 50 a is configured for receipt of a series of panels 132, 134 and136. Stripper plate 50 a can comprise, for example, static-reducedplastic having a thickness of greater than {fraction (3/16)} inches, andpanels 132, 134 and 136 can comprise, for example, aluminum. In theshown embodiment, panels 132, 134 and 136 are held to stripper plate 50a by a plurality of screws 138 (only some of which are labeled). It willbe recognized, however, that other mechanisms can be utilized forholding panels 132, 134 and 136 to stripper plate 50 a, includingriveting. Alternatively, panels 132, 134 and 136 can be molded as partof stripper plate 50 a.

Panels 132, 134 and 136 comprise ribs 140, 142 and 144, respectively(only some of which are labeled). Ribs 140, 142 and 144 can assist insupporting board assembly 10. Specifically, IC chips 12 are frequentlyprovided on both an upper surface of circuit board assembly 10, and abottom surface (not shown). Ribs 140, 142 and 144 (also referred to asblocks) have upper surfaces 141, 143 and 145, respectively, whichcontact the bottom surfaces of circuit boards 11, 13 and 15 at locationsbetween the IC chips 12 on the bottom of the board. Preferably, suchupper surfaces are provided at a height approximately equal to athickness of integrated circuit chip components 12. Accordingly, whenboards 11, 13 and 15 are rested on panels 132, 134 and 136,respectively, the boards rest on the upper surfaces of blocks 140, 142and 144 while leaving integrated circuit chip components on theunderside of boards 11, 13 and 15 extending between block upper surfaces141, 143 and 145 and panels 132, 134 and 136. An exemplary block height(or thickness) of blocks 140, 142 and 144 for a DRAM having IC chips 12with a TSOP dimensional package is 0.040 inches ±0.005 inches. Asanother example, if IC chips 12 have a SOJ dimensional package, theblock height is preferably 0.140 inches ±0.005 inches.

Blocks 140, 142 and 144 can be formed as one piece with panels 132, 134and 136. Alternatively, blocks 140, 142 and 144 can be formed asdiscrete pieces from panels 132, 134 and 136 that are subsequentlyfastened to the panels.

In the shown embodiment, blocks 140, 142 and 144 are provided in aone-to-one correspondence with integrated chip packages 14. Also, is inthe shown exemplary embodiment each of panels 132, 134 and 136 isidentical to one another, and in a one-to-one correspondence withindividual boards 11, 13 and 15. It is to be understood, however, thatthe invention encompasses other embodiments (not shown) wherein theblocks are not provided in a one-to-one correspondence with packages 14,wherein the panels are not identical to one another, and wherein thepanels are not in a one-to-one correspondence with the individualboards.

Pins 60 extend upwardly beyond upper surfaces 141, 143 and 145 of blocks140, 142 and 144, and are configured to retain circuit board assembly 10over stripper panel 50 a. In the shown embodiment, pins 60 do not extendthrough panels 132, 134 and 136. However, it is to be understood thatthe invention encompasses other embodiments wherein pins 60 do extendthrough such panels.

FIG. 3 shows a side perspective view of actuator 112. In such view itcan be seen that several ports 150, 152, 153, 154. 155 and 156 areprovided between actuator 112 and gas source. 120. Valves (not shown)are provided between source 120 and one or more of ports 150, 152, 153,154, 155 and 156. Such valves enable fluid to be selectively flowed fromsource 120 into one or more of ports 150, 152, 153, 154, 155 and 156 toselectively control raising and lowering of forcer plate 104 withactuator 112. For instance, flow of gas into port 152 can force apneumatic cylinder to lift forcer plate 104, and flow of gas into port150 can force the pneumatic cylinder to lower forcer plate 104.

Ports 154 and 156 are connected to release valves 163 and 165,respectively, which enable a pressure on at least one side of thepneumatic cylinder of actuator 112 to be maintained at ambient pressure(generally, about 1 atmosphere). Specifically, release valves 163 and165 comprise outlet ports 157 and 159, respectively, which vent to asurrounding environment. Persons of ordinary skill in the art willrecognize that one or more of ports 150, 157 and 159 are utilized as gasoutlet ports during lifting of forcer plate 104, and port 152 comprisesa gas inlet port during such lifting. In preferred embodiments of thepresent invention, the release valves are associated with an outlet sideof actuator 112 to enable equilibration of a pressure at such outletside to ambient prior to (and/or during) lifting of forcer plate 104.Specifically, the release valves enable gas to be drained from outletlines (more specifically, the gas is drained through ports 157 and 159which are open to ambient conditions) prior to, and/or during, liftingwith the actuator. Actuator 114 (FIG. 2) is preferably identical toactuator 112 and connected to an identical valve and port assembly asthat shown connected to actuator 112. Accordingly, actuator 114 is alsoconnected with release valves configured to equilibrate a back-pressureof the actuator to ambient prior to, and/or during, lifting of stripperpanel 50 a. The equilibration of pressure at the outlet ends of both ofactuators 112 and 114 to ambient during a lifting operation can enableboth actuators to have an identical back-pressure during the liftingoperation. This can facilitate having both actuators lift simultaneouslyand in unison. Such simultaneous lifting can avoid distortion (such as,for example, bending) of circuit board assembly 10 during the lifting.

Stripper plate 50a has an upper planar surface 160 and a pair ofopposing ends 162 and 164. Opposing ends 162 and 164 overlie forcerplates 104 and 106, respectively. In operation, actuators 112 and 114are utilized to lift opposing ends 162 and 164 simultaneously and inunison. Such can be accomplished by, for example, maintainingapproximately equal gas pressure at both of actuators 112 and 114 duringlifting, and is found to reduce breakage of integrated circuit packagesrelative to prior art methods. The term “approximately” in the previoussentence is utilized to indicate the gas pressure at both actuators isequal within operational parameters.

A method of operation of separator 100 is described with reference toFIGS. 4-6. In referring to FIGS. 4-6, subplate 48 a is referred to as abase, and stripper plate 50 a is referred to as a support. Referringfirst to FIG. 4, circuit board assembly 10 is shown retained on support50 a. Specifically, circuit board assembly 10 is placed over supportupper surface 160 with pins 60 extending through orifices 19 of thecircuit boards 11, 13 and 15. Pins 60 and board assembly 10 are alignedsuch that each of the integrated circuit packages 14 is retained to thesupport 50 a by at least one pin, and, in the shown embodiment, isretained by 2 pins. In the FIG. 4 processing step, actuators 112 and 114(FIG. 2) are in a lowered position.

Referring to FIG. 5, the individual integrated circuit packages 14 areseparated from one another by cutting through boards 11, 13 and 15.

Referring to FIG. 6, actuators 112 and 114 (FIG. 2) are utilized tovertically displace support 50 a from base 48 a. Preferably, suchvertical displacement comprises lifting both of ends 162 and 164 ofsupport 50 a substantially simultaneously and substantially in unisonwith one another. (As used in the preceding sentence, the term“substantially” indicates that the lifting of both ends is simultaneousand in unison within operational parameters.) In exemplary applicationsthe upper surface 160 of support 50 a is level prior to the lifting andremains level during the lifting. The lifting of support 50 a releasesseparated circuit packages 14 from pins 60. After such release, support50 a can be, for example, manually lifted from pins 108 and 110, and theseparated packages removed from support 50 a.

In compliance with the statute, the invention has been described inlanguage more or less specific as to structural and methodical features.It is to be understood, however, that the invention is not limited tothe specific features shown and described, since the means hereindisclosed comprise preferred forms of putting the invention into effect.The invention is, therefore, claimed in any of its forms ormodifications within the proper scope of the appended claimsappropriately interpreted in accordance with the doctrine ofequivalents.

What is claimed is:
 1. An integrated circuit package separator forseparating integrated circuit packages from a board comprising aplurality of integrated circuit components bonded thereto, thecomponents extending outwardly from the board, the board having aplurality of holes extending within it, the separator comprising: a basehaving a plurality of pins extending upwardly therefrom; a support overthe base and having an upper planar surface, the support having aplurality of holes extending there through and a pair of opposing ends,the pins extending through the holes and upwardly beyond the upperplanar surface of the support; the support and pins being configuredsuch that the pins extend into the holes in the board when the board isplaced over the support upper planar surface; a pair of actuatorsbeneath the support and configured to vertically displace the supportand lift the support off the pins, the actuators comprising a firstactuator proximate one of said opposing ends and a second actuatorproximate the other of said opposing ends; a panel over the support; aplurality of blocks over the panel, the blocks having upper surfaces andbeing configured to support the board while leaving the integratedcircuit chip components extending between the block upper surfaces andthe panel; and a cutting mechanism configured to cut the board while theboard is over the panel and to thereby separate the integrated circuitpackages from one another.
 2. The separator of claim 1 wherein the pinsalign with the board such that each of the separated integrated circuitpackages is retained to the support by at least one pin.
 3. Theseparator of claim 1 wherein the pins align with the board such thateach of the separated integrated circuit packages is retained to thesupport by at least two pins.
 4. The separator of claim 1 wherein theactuators are pneumatically powered.
 5. The separator of claim 1 whereinthe actuators are coupled to the support through first and second liftmembers, respectively; the lift members having substantially planarupper surfaces and the base having a substantially planar upper surface,the substantially planar upper surfaces of the lift members beingsubstantially flush with the base substantially planar upper surface. 6.The separator of claim 1 wherein the actuators are coupled to thesupport through first and second lift members, respectively; at leastone of the lift members having at least one post extending upwardlytherefrom, the at least one post extending through a hole in thesupport.
 7. The separator of claim 1 wherein the actuators are coupledto the support through first and second lift members, respectively; thefirst and second lift members each having at least two posts extendingupwardly therefrom, the posts extending through holes in the support. 8.The separator of claim 1 wherein the posts are tapered, the taperedposts being wider at respective lift members than above respective liftmembers.
 9. The separator of claim 1 wherein the actuators arepneumatically powered; the actuators each comprising a pair of gasports, one of each pair of ports being a gas inlet when the actuatorlifts the support and the other port of each pair of ports being a gasoutlet when the actuator lifts the support; the separator furthercomprising at least one pressure release valve in fluid communicationwith the gas outlets.
 10. The separator of claim 1 wherein the actuatorsare pneumatically powered; the actuators each comprising a pair of gasports, one of each pair of ports being a gas inlet when the actuatorlifts the support and the other port of each pair of ports being a gasoutlet when the actuator lifts the support; the separator furthercomprising at least two pressure release valves, one of the pressurerelease valves being in fluid communication with one of the gas outlets,and an other of the pressure release valves being in fluid communicationwith the other of the gas outlets.
 11. The separator of claim 1 whereinthe actuators comprise respective substantially co-planar surfacespositioned beneath respective opposing ends of the support.
 12. Theseparator of claim 1 wherein the panel is fastened to the support. 13.The separator of claim 1 wherein the blocks are in a one-to-onecorrespondence with the integrated circuit packages on the board. 14.The separator of claim 1 comprising more than one panel over thesupport, each panel having blocks associated therewith.
 15. Theseparator of claim 1 wherein the blocks are fastened to the panel. 16.The separator of claim 1 wherein the blocks are one-piece with thepanel.
 17. The separator of claim 1 wherein the pins do not extendthrough the panel.
 18. The separator of claim 1 wherein the basecomprises a substantially planar upper surface, and wherein the supportdefines a substantially planar upper surface over an entirety of theupper surface of the base.
 19. The separator of claim 1 wherein thesupport is devoid of pins.
 20. The separator of claim 1 wherein thepanel is devoid of pins.
 21. The separator of claim 1 wherein the basecomprises a substantially planar upper surface terminating to defineoutermost lateral edges, and wherein the support defines a substantiallyplanar upper surface over an entirety of the upper surface of the baseand extending laterally beyond the outermost lateral edges of the base.